Download Diseases of Young Calves

chapter
Section 7
23
41
Diseases
of Young Calves
by James O’Shaughnessy
Introduction
Young calves are vulnerable to a range of diseases;
careful management can prevent unnecessary mortality.
1 What are the key points in protecting calf health?
2 How do I
3 How do I
4 How do I
5 How do I
6 How do I
manage
manage
manage
manage
manage
scour/diarrhoea?
pneumonia?
navel ill/joint ill?
coccidiosis?
clostridial diseases (older calves)?
237
chapter
Diseases
of Young Calves
41
1
What are the key points in protecting calf
health?
Colostrum
Ensure the calf receives sufficient colostrum
(see chapter on colostrum).
Navel treatment
Treatment of navels is outlined in the section on calving
and neonatal care.
2 How do I manage scour/diarrhoea?
Environment
The calf’s environment needs to be clean, dry and well
ventilated. Particular attention should be paid to the calving
pens and creep areas. Bedding should be regularly added to
these areas. You should be able to kneel on the bedding
without your knees getting wet. All areas where calves are
should be cleaned out and disinfected between batches of
calves. All equipment (e.g. stomach tubes, calving ropes,
buckets) used should be cleaned and disinfected after use.
Consult with your vet on an appropriate disinfectant.
What causes calf scour?
Viruses (rotavirus, coronavirus).
Bacteria (E. coli, salmonella).
Parasites (cryptosporidia, coccidiosis*).
*Coccidiosis causes scour in older calves (three weeks
and older).
Early identification and removal of sick calves
Any calves showing signs of sickness (scour, pneumonia etc.)
should be removed immediately along with their dam and
placed in a pen which is designated for sick animals only.
They should only return to the group when the calf has
recovered from illness. The pen which is used for sick
animals must be cleaned and disinfected after each use. It
must not be also used as an isolation facility for purchased
animals/returning from shows.
Where do my calves ‘pick up’ calf scour?
• A calf picks up these infections in either the calving pens
or any other calf housing areas. All the agents that cause
calf scour (viruses, bacteria and parasites) are passed out
in the dung from other cows and calves. Without regular
cleaning and disinfecting of all calf areas (e.g. calving
pens, creep areas), these agents build up in the calf’s
environment.
Mixing of different age groups
Try and avoid unnecessary mixing of calves of different age
groups. Older calves, which have been exposed to more
disease causing agents, can potentially transmit disease to
younger calves. This is especially important at herd events
(TB testing, scanning or dosing) where different groups of
cattle are brought together. At herd events such as these
keep groups from mixing with each other.
Avoid overstocking
Have adequate space, both at housing and at pasture for
calves. For example, having too many calves in the one
creep area will make it more difficult to keep it clean and
well-bedded but will also act as a stressor for these calves.
Stressors such as overcrowding make calves more
susceptible to disease.
238
Vaccination
Advice should be sought from your vet when deciding on a
vaccination programme for a particular disease. This includes
advice on vaccine type, dose, timing of vaccination, and
method of administration. The use of vaccines is the main
method in preventing clostridial diseases (blackleg, tetanus
etc.) but should not be regarded as the sole method of
prevention of calf scour and pneumonia.
What are the two most common causes of calf scour
in Ireland?
Rotavirus and cryptosporidia.
What is the first thing to do when I see a calf with
scour?
• Remove that calf along with its mother from the rest of
the group and place in the pen designated for sick animals
only. Note that this pen for sick animals must be cleaned
and disinfected after every time that it’s used.
How do I treat a calf with scour?
• Allow the calf full access to the cow (do not take the calf
off milk)
• Provide extra fluids/electrolytes to replace the fluids lost by
the calf. Give the calf at least one electrolyte feed during
the day (in 2 litres of water) and depending on the severity
of the scour, a second feed can be given later in the day.
chapter
41
Does a calf with scour need antibiotics?
In general they don’t. As most cases of scour are caused by
viruses and parasites (which don’t respond to antibiotics), the
use of anti-bacterials is a waste of money and may lead to
bacterial resistance on your farm.
So when do I give a calf with scour antibiotics?
• A calf with scour requires antibiotics (+ veterinary
assistance) in the following cases:
• If the calf’s temperature is outside the normal range (38.5-39.5°Celsius).
• If the calf is weak, unable to stand, has sunken eyes.
3 How do I manage pneumonia?
Any calf with signs of several or all of the following:
• Nasal discharge, coughing, heavy breathing, increased
breathing rate (‘blowing’/panting), in addition to signs
such as dullness, reduced appetite, drooped ears and
fever.
What are the main disease causing agents?
Viruses (RSV, PI3, IBR, BRCV and BVDV)
Bacteria (Pasteurella, Haemophilus and Mycoplasma).
How does pneumonia spread?
• If the calf won’t suck.
• Droplets coughed up by or exhaled from other
cattle/calves.
• If the calf is passing blood in its dung.
What are the key risks?
Should I take dung samples from calves with scour
and send to the laboratory?
• Calves not getting enough colostrum.
Yes, in the following cases:
• Calf scour is a regular problem on my farm.
• A number of calves have scour at the one time.
• The treatment that I normally use doesn’t work.
What about vaccination?
• Vaccination can help in the prevention of calf scour, but:
• It should not be seen as the sole answer to prevention.
• For vaccination to work, the calf has to be given adequate
volumes of colostrum as soon as possible after calving.
• Poorly-ventilated buildings (favours spread of disease).
• Stress (Overcrowded cattle sheds, mixing of different
groups of cattle, sudden changes in weather/diet).
• Unnecessary mixing of calves of different age groups
(older calves can act as carriers of many of the agents
that cause pneumonia).
• In older calves at pasture, lungworm can act as the
‘trigger’ in calves developing pneumonia.
What do I do if I have a calf with pneumonia?
• Remove this calf along with its dam and place in the sick
pen. Treat the calf under instructions from your vet. Once
the calf has been removed from the group, take another
look at the rest of the calves in that group. As pneumonia
tends to spread rapidly in a group of calves, you may
have to treat all the calves in the same pen (under
veterinary advice/supervision).
If calf pneumonia is a regular problem on my farm
what should I do?
• You need to discuss with your vet all the key
risks mentioned above. Some or all of these will be
contributing to your problems with calf pneumonia.
239
chapter
41
Diseases
of Young Calves
Should my vet also take samples from calves?
How is the disease spread?
• Yes if calf pneumonia is a regular problem on the farm.
This may help in deciding what vaccine to subsequently
use on the farm.
• The disease is spread by the faecal-oral route.
Calves ingest oocysts (the environmental stage) that have
been passed in the dung by other calves/cows. The calf
ingests these oocysts, which if ingested in high doses,
results in the development of clinical signs of disease. It
takes about three weeks from the time a calf ingests these oocysts before clinical signs appear.
Should I regard vaccination as the most important tool
in combating calf pneumonia?
• No. Most of the agents that cause calf pneumonia are
widespread in the cattle population. So although
vaccination will help, it is highly important that you (in
conjunction with your vet) try and determine the underlying
problem on the farm that is causing you to have regular
cases of calf pneumonia. Is it a lack of colostrum? Is it due
to overcrowding? Is ventilation in the shed poor? etc.
4 How do I manage navel ill/joint ill?
What are the main risk factors for coccidiosis?
Environmental hygiene
• Wet and dirty bedding.
• Overcrowding (both at housing and at pasture).
• Badly-ventilated sheds.
How can I reduce the number of cases of these
on my farm?
• Dirty feed and water troughs.
• Ensure calves get enough colostrum.
• Calved heifers and cows with long dirty tails (major risk
factor for very young calves who are trying to suckle.
• Improve the hygiene of the calf’s environment. Regular
cleaning and disinfection of calving pens and creep areas.
Provide ample bedding for calves as referred to earlier in
this chapter.
Stress
• Avoid stressors on the calf. Mixing of different age groups
or sudden changes in diet can act as stressors.
• Navel treatment (the principles of navel care are referred
to in the section on care of the newborn calf).
Nutrition
Improving these three key factors above will have the
added benefit of improving overall calf health.
• Calves that have not received enough colostrum or are not
getting enough milk from their dams have a reduced ability
to deal with infection.
5 How do I manage coccidiosis?
What is coccidiosis?
Coccidiosis is a parasitic disease of calves (three weeks of
age and older), weanlings, yearlings and, less commonly,
older cattle. It results in damage to the intestinal lining as
a result of the parasite multiplying in the intestine.
What are the clinical signs?
• The clinical signs can vary from mild diarrhoea to severe
blood-stained diarrhoea accompanied by the calf straining.
Often the only sign noticed is a calf with a wet/soiled tail.
How can I reduce the incidence of disease in my herd?
Hygiene
• Ensure all housing and creep areas are clean, dry and well
ventilated. Clean and disinfect housing areas between
batches of calves. This parasite is resistant to most
disinfectants. Discuss with your vet the most appropriate
disinfectant to use.
• Avoid overcrowding at housing.
• Water and feed troughs need to be kept clean. Remove all
faecal material.
• Ensure the tails of all cows and heifers at calving are
trimmed. This reduces the risk of the calf ingesting faecal
material when trying to suckle.
240
chapter
41
Avoid stressors
• The unnecessary mixing of different age groups or
sudden changes in diet.
Nutrition
• Ensure calves receive adequate colostrum and are well
nourished subsequently.
Preventive treatments
• Discuss with your vet the options available for using
preventive and therapeutic measures.
6 How do I manage clostridial diseases
in older calves?
What is clostridial disease?
Spores produced by the bacteria are eaten by the animal
during grazing. These spores, after ingestion, can be found
in muscle, liver and spleen. If that area of muscle where the
spores are located is subsequently damaged (injury, bulling
etc.), the spores germinate and produce a fatal toxaemia.
Generally the animal is found dead. On rare occasions,
the animal may still be alive. If the area of muscle damage
(lesion) is in a limb, the animal will be severely lame. As the
disease progresses, there will be a build up of gas in the area
where the lesion is. The lesion will be spongy to feel and you
can hear gas crackling when you press on the lesion.
What about treatment?
On the rare occasion an animal is still alive contact your vet
immediately. He or she will prescribe the necessary antibiotic
that you need to use.
Clostridia are a family of soil-borne bacteria that cause a
number of conditions in cattle. One of the most common
conditions is blackleg. What do I need to know about
blackleg?
The best form of treatment is prevention. If your farm has
a history of blackleg, vaccinate stock before they go to
pasture. Depending on the vaccine you use, follow the
instructions as per the information leaflet that
accompanies the product.
Blackleg is mainly a disease of grazing animals. It can also
occur in housed animals that have grazed infected pastures.
It mostly affects cattle from six months to two years of age. It
can, however, occur in calves a few months old.
For further information on calf health,
go to www.animalhealthireland.ie
241
242
chapter
Section 7
42
23
Significant diseases
in beef cattle
by Colm O’Muireagáin, Ann Sharpe, Peter O’Neill, Ian Hogan, Mícheál Casey and Dónal
Sammin (DAFM Veterinary Laboratory Service)
HI-RES landscape
version of this shot
needed.
Introduction
Good breeding, calf-rearing, grassland management, winter feeding,
housing, biosecurity, etc. are essential to maintaining good health
in beef animals. The focus of this chapter is on some specific disease
problems that can cause significant loss or concern for beef rearing
and fattening enterprises.
1 How do I deal with diseases causing ill-thrift in cattle at grass?
2 How do I prevent/manage respiratory disease in housed cattle?
3 What are the common causes of sudden death in cattle?
4 How can disease affect reproductive performance in cattle?
5 What are the regulatory controls on specific infectious diseases of cattle?
243
chapter
1 How do I deal with diseases causing
ill-thrift in cattle at grass?
Ill-thrift is failure to maintain condition and bodyweight
(adults) or to grow as expected (young stock). The major
causes of ill-thrift in cattle at grass are: (1) malnutrition; (2)
parasitism and (3) other chronic or long-standing disease
Good grassland management will ensure that cattle have
access to plenty of leafy grass that they can readily digest
and will provide all of their energy requirements for
maintenance and growth. In addition, the diet must also
provide small amounts of certain essential chemical elements
(trace elements). Deficiencies of any of these micronutrients
can result in ill-thrift.
Under Irish farming conditions, copper deficiency is the most
common deficiency to affect beef cattle. Rather than a lack
of copper in the soil an excess of soil molybdenum, iron or
sulphur may be interfering with the uptake of copper. Other
less common but significant trace element deficiencies are
cobalt deficiency and selenium deficiency.
In their second year they will usually benefit from immunity
acquired from ‘trickle infection’ acquired in their first grazing
season.
Key
fact
“
Autumn-born calves are more susceptible as they are turned
out in the spring after weaning with little immunity and are
often kept as same-age groups.
How to
Recognise roundworm infestation?
How to
Scour, faecal staining of the hindquarters and tail; affected
calves look empty and will lose weight
Recognise copper deficiency.
When/where does it occur? Young cattle
Ill-thrift, and in severe cases, loss of coat colouration provide
circumstantial evidence of deficiency. Your vet’s knowledge
of the area’s copper/molybdenum status will be helpful, and
laboratory tests can confirm it
Key risk
Young cattle are most at risk.
!
What can I do about it?
Copper can be supplemented in a variety of ways (feed,
injections, long-acting boluses). However copper poisoning is
a real risk, so it should only be supplemented on farms with
proven deficiency.
Parasites
The most economically-significant parasitic infestation is that
caused by roundworms in the gut. Younger animals are more
likely to be affected and severe infestations can result in loss
of condition and even death. Climatic and environmental
conditions heavily influence the severity of infestations.
Infested animals pass worm eggs in their faeces and the
larvae that hatch from these infest other cattle as they graze.
244
Pasture burdens of larvae tend to snowball in the second
half of the grazing season and this usually coincides with
decreasing grass quality. Spring-born suckler calves are
rarely affected by worms in their first grazing season because
they don’t consume enough grass to accumulate significant
burdens, and because the ‘dilution effect’ of co-grazing with
their relatively resistant mothers prevents the build up of
dangerous levels of pasture contamination.
“
42
Significant diseases
in beef cattle
What can I do about it? Appropriate pasture management
and the strategic use of anthelmintics
Lungworm infestation causes a parasitic pneumonia or
“hoose” and can cause severe disease in suckler calves
and weanlings, regardless of when they are born. Hoose
should be considered when cattle are seen to be coughing
at pasture. This will be exacerbated by exercise, and
open-mouth breathing is common.
Laboratory tests (faecal analysis) may be required to
differentiate hoose from other respiratory diseases.
chapter
42
Liver fluke infestation can affect all ages of cattle, but like all
parasitic diseases, tends to be more severe in younger cattle.
This parasite depends on a snail to complete its life cycle and
it will be more prevalent on poorly drained land and during
wet years. Rumen fluke can cause very severe scour and
weight loss in some years on some farms (heavy rainfall,
flooded pastures) but, as for many parasitic infestations,
infestation is common but disease is rare.
Further information on the control of parasitic diseases may
be obtained from the Animal Health Ireland website at
www.animalhealthireland.ie
Other chronic diseases
Respiratory disease, which is dealt with in more detail in
the next section, may also occur at grass. Many outbreaks
are caused by viruses and can be confused with hoose in the
early stages (see above). Residual lung damage resulting
from respiratory disease in housed calves may continue to
affect the performance of young animals after turnout. Other
diseases that occur in housed calves in early life and can
affect the later performance of beef suckler calves at grass
include include navel infections or diarrhoea.
Bovine Virus Diarrhoea (BVD) can cause ill thrift in
persistently-infected (PI) calves, which have been infected
with the virus before birth, although some PIs show little or
no ill effects. This disease is the subject of a national
eradication programme being promoted by Animal Health
Ireland, and based on testing of newborn calves for the virus.
More information on this programme can be obtained at
www.animalhealthireland.ie
Johne’s Disease is a progressive and insidious disease that
can cause scour and weight loss in adult cattle usually over
four years of age, and is a difficult disease to control within
herds. Laboratory tests for the disease are difficult to
interpret; they only give a guide to the herd status, and are
not useful for individual animals.
Control programmes are built around preventing infection
in early life through management practices that limit the
exposure of calves to the faeces of other cattle, and
avoiding the purchase of animals that are incubating the
disease. Whole-herd individual animal testing as an ancillary
aid to early detection of infection. A national voluntary control
programme for control of Johne’s Disease is being developed
by Animal Health Ireland.
www.animalhealthireland.ie
2 How do I prevent/manage respiratory disease in housed cattle?
Respiratory disease in housed cattle can be a very
significant cause of loss in beef enterprises, particularly
in weanlings. There are the obvious costs associated with
animals which die of the disease or which require
veterinary treatment. However, the hidden costs
associated with less severe disease in the remainder of the
group (failure to thrive during the illness and subsequent
recovery period and the fact that some surviving cattle never
fully recover or thrive after the illness) are often of much
greater economic significance.
What is respiratory disease and
how do I recognise it?
Respiratory disease usually involves the upper airways
(the nasal passages and the trachea or windpipe) in which
case the signs are nasal discharge and coughing. In some
cases the disease extends to the lower airways (the lungs),
which by definition is referred to as “pneumonia” and in
which cases animals are likely to have difficulty breathing.
Animals with respiratory disease are also likely to show
general signs of illness such as dullness and a poor appetite.
What causes respiratory disease in groups of cattle?
Respiratory disease in groups of housed cattle is usually
associated with viral and/or bacterial infection of the
airways. Cattle become infected by inhaling infective
droplets produced by other infected cattle. The most
significant viral agents are bovine herpesvirus
1 which causes infectious bovine rhinotracheitis (IBR) and
bovine respiratory syncytial virus (RSV). Parainfluenza-3
(PI3) virus is less important and Bovine virus diarrhoea virus
(BVD) may be involved in some cases.
These viruses can cause disease by themselves or
damage the defence mechanisms of the upper airways
allowing secondary bacterial infections of the lungs.
The most significant bacterial agents are Mycoplasma
species, Mannheimia haemolytica, Pasteurella multocida
and Histophilus somni.
245
chapter
42
Significant diseases
in beef cattle
Key risk
!
When is respiratory disease most likely
to occur?
• After buying-in and mixing of cattle from different sources
(increases the risk of exposure to different infectious agents that cause respiratory disease)
• Where there is overcrowding and/or poor ventilation
(increases the risk of infection)
• Where cattle have been subjected to one or more “stress”
factors immediately before housing such as weaning,
castration, dehorning, transport, etc. (reduces the animals
natural ability to fight off infection and resist disease)
What to do when it occurs - how is it treated?
There is no specific treatment for viral infections but in the
case of an IBR Infectious Bovine Rhinotracheitis outbreak it
may be advisable to vaccinate other animals in the group
if they are not yet displaying signs of illness. An intranasal
vaccine can provide protection within 24-48 hours but this
should only be undertaken on veterinary advice and following
laboratory confirmation of the diagnosis (this is usually based
on testing of nasal swabs collected from affected animals).
Antibiotic treatment may be administered or prescribed by
a veterinary practitioner to control secondary bacterial
infections.
If possible, coughing calves should be kept separately from
unaffected calves and you should consider treatment for
hoose if calves were coughing at/before hoosing.
What practical steps can I take to prevent the
occurrence of respiratory disease?
Where cattle are bought-in, follow the biosecurity guidelines
detailed elsewhere in this manual – this will reduce the risk
of introducing and spreading infectious diseases.
• Ensure that housing is adequately ventilated and drained.
The ideal airflow is generated by a pitched roof where
spent warm air can escape at the ridge and be replaced
by fresh, cool air entering below the eaves - the objective
is to provide for adequate air movement at calf head
height. A strong smell of urine or slurry in a house or
condensation on the underside of the roof are indications
that ventilation may need to be improved. Adequate
drainage is important to prevent excessive humidity while
both drainage and ventilation are important in reducing the
exposure of cattle to infective droplets in the air.
246
• Reduce or eliminate “stress” factors that contribute to the
development of disease – (See Section on Managing
Weaning in this Beef Manual)
• Consult with your veterinary practitioner about the use of
vaccination before housing.
3 What are the common causes of sudden
death in cattle?
Finding one or more animals dead which had not
previously shown any signs of illness is not an uncommon
experience but can be a very distressing one. The herd owner
or stockperson will not be at ease until a cause can be
identified and the risk to other cattle reduced or eliminated.
Here we consider some of the more common causes of
sudden death in cattle under Irish farming conditions and
what steps can be taken to prevent further losses. The list
below is not exhaustive and these causes are not ranked
in any particular order.
“Blackleg” - Clostridium chauveoi
This disease most commonly occurs in young cattle and is
caused by infection with the bacterium Clostridium chauveoi.
An inactive form of the bacterium (spores) present in the
environment can be acquired by the animal and can then
remain dormant in muscle. Trauma and bruising to muscles,
creates the necessary conditions (a reduction in the amount
of oxygen) for the bacteria to be activated.
As the bacteria proliferate they produce large amounts of
toxin which account for sudden death. The proliferating
bacteria produce gas bubbles and discolouration of muscle
which may aid a field diagnosis. The disease may be
prevented by vaccination.
Other clostridial diseases
Malignant oedema is similar to blackleg, except that the
damage to muscle which facilitates the proliferation of the
bacteria is usually caused by a wound or injection site and
the disease may be caused by any one of a number of different Clostridial species. The disease may be prevented by
vaccination.
Table 1:
Cattle R
Cattle O
Dairy
Mixed
Sheep
Tillage
Cattle R
Cattle O
Dairy
Mixed
Sheep
Tillage
chapter
42
In Black disease and Bacillary haemaglobinuria (Clostridium
novyii), the site of bacterial proliferation is the liver where the
tissue damage is caused by migrating liver fluke. In addition
to vaccination, both of these diseases may be prevented by
controlling liver fluke infestation.
Clostridial enterotoxaemias are caused by the proliferation of
Clostridium perfringens types B or C and the production of
toxin in the intestines.
Hypomagnesaemia or “Grass tetany”
A sudden drop in blood levels of magnesium is one of the
most common causes of sudden death in adult beef cattle
at pasture. It usually occurs in lactating animals in spring
and autumn and is associated with decreased availability of
magnesium from the diet. Stress factors such as inclement
weather conditions are contributing factors.
If found alive, affected cattle show very marked nervous
signs; they are hyper-excitable and very rapidly go down
in convulsions, whole body tremors and thrashing of limbs.
When animals are found dead, one of the hallmarks is
disturbance of the ground around the carcase. Urgent
veterinary treatment may save some animals.
Prevention: animals at risk should be supplemented
with magnesium during risk periods - various methods,
including pasture dusting, water supplementation or
provision of magnesium licks are available.
Lead poisoning
Lead is one of the most commonly recognised causes of
poisoning in cattle and is usually attributed to cattle having
access to old car batteries or to lead-based paints. Vehicle
sump oil, old vinyl from floor coverings and car seat
covers are also potential sources of lead. On rare occasions,
catastrophic losses have occurred where discarded
batteries have been ensiled and this silage then fed to cattle.
Prevention simply requires that cattle are not exposed to
potential sources of lead.
Bloat
Gas is produced during the normal digestive processes in the
fore-stomachs and cattle belch frequently to discharge this
gas and relieve pressure.
(i) where there is an obstruction along the oesophagus or gullet or (ii) where there is a rapid fermentation in the stomachs
producing a froth which cannot be belched up - this
happens in some cases where cattle are grazed on lush
clover-rich pastures.
Ruminal acidosis or “Barley poisoning”
If cattle suddenly gain access to and consume large amounts
of carbohydrates such as cereal grain or other concentrate
feeds, a very rapid fermentation process occurs in the
fore-stomachs generating large amounts of lactic acid and
producing a type of drunkenness which if sufficiently severe
and untreated can be fatal.
Prevention involves gradual introduction of concentrate feeds
and providing sufficient trough space.
Electrocution/Lightning strike
This is an occasional cause of sudden death in cattle with
few signs of a struggle; occasionally scorch marks may be
observed on the carcase. Electrocution (which should be
considered where more than one animal is found dead at the
same spot) can occur through contact with fallen power lines
or with stray electric current in sheds – care should be taken
before approaching the carcase(s) to ensure that the source
of electrocution is not still live.
White Muscle Disease (Selenium/Vitamin E deficiency)
This is a disease mainly of fast-growing beef calves which
can result in sudden death if the heart muscle is affected.
Calves may show signs of muscle stiffness before death
or are often found dead particularly at the onset of a herd
problem. Confirmation of the diagnosis requires laboratory
investigation.
Intestinal obstruction or other abdominal crisis
This includes a number of spontaneously occuring conditions
such as intestinal torsion (twisted gut), intestinal entrapment,
intussusception, abomasal ulceration and peritonitis; such
conditions normally only affect one or two animals in a group.
Bloat occurs where the stomachs become distended with gas
or frothy fluid and can arise in two circumstances:
247
chapter
42
Significant diseases
in beef cattle
4 How can disease affect reproductive
performance in cattle?
Most infertility in beef herds is associated with the kind of
management, nutritional and heat detection issues described
in other chapters.
How to
Determine how diseases affect
reproductive performance?
Infections can have a significant impact on the cow’s capacity
to produce viable calves, resulting in abortions, stillbirths, or
weak calves. This impact can come from infections of the
uterus (womb) after calving, preventing the cow from going
back in calf, or from a variety of diseases which affect
different stages of reproduction. Diseases like BVD may cause
early embryonic death or abortion later in pregnancy, other
infections can cause foetal death at any stage e.g.
Salmonella Dublin.
Diseases also differ in the rate of abortion they will cause.
Some diseases will cause sporadic abortions (e.g. listeriosis),
while other diseases can cause abortion storms, or a large
number of abortions together, causing an immediate crisis,
e.g. salmonellosis or neosporosis.
What causes abortion?
Any illness where a cow has a very high temperature can
result in abortion. Any infectious agents that cross the
placenta in the pregnant cow and that cause damage to
the foetus and/or the placenta can also result in pregnancy
loss. When infection occurs in early pregnancy the resulting
embryo loss may only be apparent when cows are found to
be “empty”.
Illness at later stages of pregnancy can result in the
cow throwing the foetus (abortion) or delivering a dead calf
(stillbirth). Sometimes there is a delay between the death of
the foetus and its delivery such that aborted foetuses and
membranes are very often poorly preserved.
Individual or “sporadic” abortions may be caused by an
infectious agent (Arcanobacter pyogenes, Bacillus spp., fungal
agents) or non-infectious attack during pregnancy. Multiple
abortions occurring within a relatively short period of time (i.e.
an abortion storm) suggest that several cows in the herd have
been exposed to an abortion-causing infectious agent.
248
The list of infectious agents includes:
Brucellosis, which is a very contagious disease causing
abortion storms and is scheduled and notifiable. Abortion
usually occurs after five moths of pregnancy and the placenta
and fluids released at calving are highly infectious. The
Republic of Ireland is officially brucellosis free but the disease
is still present in Northern Ireland. Herdowners are legally
obliged to have any cow or heifer which aborts tested twice
for brucellosis, this can be an opportunity to
take another sample to test for other diseases.
Leptospirosis can cause abortion at any time during
pregnancy and is among the main causes of infectious
reproductive losses in Irish suckler herds. Tests on the
aborted foetus are unsatisfactory and blood testing is
preferred to detect exposure. Control involves vaccination
in the spring.
Salmonellosis is a contagious disease which can cause
abortions from the fourth month of pregnancy. It can also
cause other illnesses in the herd. It can be detected by
culture from the aborted foetus or placenta, or by blood test.
This disease can be difficult to control, as many animals can
carry the organism without showing signs. Vaccination of the
full herd is recommended if Salmonella infectionis confirmed.
Key
risk
!
Brucellosis, leptospirosis and salmonellosis are all diseases
which can infect humans. Take steps to avoid infecting
yourself or others, seek advice if necessary
chapter
42
Neosporosis in cattle is caused by a parasite acquired from
the faeces of infected dogs or foxes, or congenitally from
the dam. Abortion normally occurs between three and eight
months of pregnancy. Infection from dogs can lead to
abortion storms while herds where congenital transmission
takes place will normally suffer sporadic abortions.
Q fever (Coxiella burnetti) is caused by a bacteria-like
organism (Coxiella burnetti) that most readily affects sheep
and goats, causing abortion. It may transfer and cause
abortion in cattle. It also affects humans.
Infected animals are infected for life and will have a greater
chance of aborting, or passing the parasite on to their heifer
calves. Neospora can be detected in the foetus or in blood
from the cow or heifer. There is no vaccine available here, so
control involves restricting the access of pets and wildlife to
animal’s feed and removing infected animals from the
breeding herd. It is not advisable to breed from the female
calves of Neospora positive animals.
Does abortion affect the cow?
Silage-associated infections:
• Quarantine the aborting cow from other cattle, especially
from other pregnant cows for 2-3 weeks until vaginal
discharge has ceased.
Mycotic abortion is caused by a fungus and usually occurs
as sporadic abortions between three and seven months of
pregnancy. The majority of these infections come from poorly
preserved fodder, and much more rarely from bedding.
Listeria and Bacillus are bacteria which are also found in
silage, especially where soil has been picked up during
harvesting
BVD causes a range of problems, including abortion. Though
BVD-related abortion can occur at any stage of pregnancy it
is more common in the early stages, while surviving calves
may be deformed or persistently infected with BVD (a PI
animal).
Tissue tagging of the foetus is a good way to check whether
BVD has caused the abortion.
Control involves eliminating PI animals from the herd, as
these animals are an overwhelming source of infection – this
is the basis of the current AHI eradication programme.
Vaccination can give increased protection from the disease
but is not effective if PI animals are left in the herd,
especially if left in contact with breeding stock.
IBR / Bovine herpesvirus-1 can cause abortion. It may be
transmitted by the semen of infected bulls. As infection is
much more common than disease, it is difficult to interpret
blood tests.
Key question
?
Aborting cows do not normally display signs of illness unless
there is retention of the foetal membranes (afterbirth) and
uterine infection; salmonellosis is an exception where many
of the aborting animals may be ill.
How to
Deal with the aborting cow
• Submit specimens to the laboratory - blood from the cow
for brucellosis and for salmonellosis, leptospirosis and
neosporosis; the foetus and afterbirth for post mortem
examination and culture.
• Hygienic precautions should be taken, especially handling
the products of abortion and any discharge from
aborting cows, as most of the infectious diseases which
cause abortion in cattle can also cause severe illness in
exposed persons.
• Hygienic disposal of contaminated material; thorough
cleaning and disinfection
• Closely monitor other pregnant cows to ensure that this is
not an “abortion storm”
Note that there is a legal requirement (legislation
for control of brucellosis) on the owner
or person-in-charge to isolate an animal that aborts
and to either notify the Department of Agriculture or
send specimens for laboratory diagnosis.
How
to
Prevent re-occurrence of abortion storm
in future years
Vaccinate cows where there is a definite diagnosis of
salmonellosis or leptospirosis
249
chapter
42
Significant diseases
in beef cattle
Key question
How do I deal with retained placentas
and womb infections after calving?
?
Infection of the uterus after calving, known as endometritis
or metritis, may lead to severe illness, or mild disease which
goes unnoticed but impairs fertility by making the womb
unsuitable for the embryo to implant often results.
• Prevent infection at calving by ensuring good hygiene of
calving facilities and equipment.
• Check high risk cows (twins, difficult calving, etc.) after
calving. Infection may be detected by a discharge from
the vulva, on handling or by ultrasound scanning.
• Veterinary attention should be sought as these infections
are difficult to cure. Retained foetal membranes, where
the placenta is still attached to the uterus after 24 hours,
will greatly increase the chance of metritis or endometritis.
• Observe the animal for signs of sickness. Consult
your vet if this occurs. Removal by hand is no longer
recommended. When the placenta has been lost,
observe the cow for metritis described above.
5 What are the regulatory controls on
specific infectious diseases of cattle?
Some infectious diseases of cattle are zoonotic
(i.e. transmissible from animals to man), e.g. bovine
tuberculosis (TB). Other infectious diseases have the ability
to spread rapidly throughout the cattle population and cause
very significant economic losses, e.g. foot-and-mouth
disease. Both categories of disease are subject to national
and international regulations and these are particularly
important when it comes to the export trade in live cattle
and beef. The World Organisation for Animal Health (OIE)
is responsible for listing infectious diseases of livestock that
should be subject to specific control measures and for
prescribing the measures that are to be used by its 178
member countries across the globe. In addition, member
states of the European Union are bound to comply with
various pieces of legislation dealing with specific diseases
of animals.
In the case of OIE-listed diseases which are known to occur
in Ireland (endemic), the Department of Agriculture, Food
and the Marine (DAFM) will most likely have a control or
eradication scheme in place to ensure continued market
access – this has been the case for bovine tuberculosis (TB),
brucellosis, and BSE.
For OIE-listed diseases that do not normally occur in Ireland
(exotic), DAFM will have made provision to ensure that they
cannot be readily introduced or that if introduced, they can
be rapidly detected and eliminated (e.g. Foot-and-Mouth
disease, Bluetongue, etc.). Animal Health Ireland was
established in 2009 to promote and develop an
alternative industry-led approach to national control of
economically-significant diseases of livestock – an industryled approach. To date it has established programmes for the
control of BVD, Johne’s Disease, IBR and subclinical mastitis
(the “Cell Check” programme) in cattle.
250
chapter
Section 7
43
23
Calving and
the Newborn Calf
by John Mee
Introduction
Calving is a high-risk event for both the cow and the calf. Common
problems encountered include difficult, abnormal or slow calvings.
The newborn calf is challenged by numerous infections which can
result in navel ill, scour and pneumonia.
1 How can I minimise the likelihood of calving problems?
2 How can I best care for the new-born calf?
251
chapter
43
Calving and
the Newborn Calf
1 How can I minimise the likelihood of
calving problems?
How
to
Prevent problems before calving
• Make sure your heifers are big enough at calving
(see chapter on replacement heifers).
• Choose an easy calving sire, particularly for heifers.
• Make sure your cows and heifers are not too fat or too thin
at calving.
•
Feed them a balanced diet during pregnancy including
trace minerals and vitamins. If you are unsure about the
trace element status of your herd, ask your vet to bleed
five cows and five heifers in late pregnancy.
• Control calving date. If calves are overdue, discuss the
options with your local vet.
• Control infections in the pregnant animal by vaccinating or eradicating diseases.
How to
• Be present at calving to resuscitate a weak calf, dress its navel and ensure it receives colostrum.
•
Resuscitate weak calves by suspending the calf upside down (max one minute), pour water over its head and sit
the calf upright. Use resuscitating drops/gels or other
resuscitating aids if available.
•
Navel ill is a problem where the calf’s immunity
and the calving environment hygiene are poor. To prevent this condition, ensure calves get adequate colostrum, dress the navel cord as appropriate, and keep the calving
bedding clean.
See chapter Managing Colostrum
• Calves should suckle the cow until they are full as soon
as possible after birth.
•
In situations where this is not feasible, research at
Teagasc, Grange has shown that feeding the calf 5% of
its birth weight (e.g. ~2 litres of colostrum for a 40 kg
calf), within one hour or so of birth, with subsequent
suckling of the dam (or a second feed) 6 to 8 hours later,
ensures adequate passive immunity.
Manage calvings to reduce problems
•
Ideally move pregnant animals to a calving unit before
they start to calve – this will generally ensure a more hygienic environment and help prevent losses due to early scours and navel/joint ill.
• Supervise but don’t necessarily intervene during calving.
Intervene if calving is not progressing normally; if two hours after the waterbag or fetal hooves appear the calf is
not born, examine the birth canal and calf with a gloved hand.
•
To avoid injuries to the calf, call the vet early if you’re not sure you can get the calf out alive. Be careful not to pull
the jack downwards too acutely before the chest comes out when assisting the calf at birth, as this can cause fractured ribs.
2 How can I best care for the new-born calf?
How to
Care for the newborn calf
• Most calves do not need help but some do – particularly
those presenting in abnormal positions or after a
prolonged calving.
252
In young calves there is a high risk of diseases such as scour
and pneumonia. See chapter on calf diseases.
Animal Health Ireland has produced a series of leaflets
on calving management and calf health available at www.
animalhealthireland.ie.
chapter
Section 7
44
Managing
Colostrum
by Mark McGee and Bernadette Earley
Introduction
The health of suckler calves depends on minimising their exposure to, and
maximising their defence against, disease. Colostrum (beestings) is the first
and most important line of defence for the calf and, a timely, adequate intake
of quality colostrum is essential. Colostrum provides food but also maternal
antibodies to protect the young calf against the infections that it is likely
to encounter in early life.
1 What is colostrum?
2 Why is consuming colostrum critical for calf health and survival?
3 What are the main factors affecting colostrum yield & quality?
4 What are the main factors affecting calf immune status?
5 When should you decide whether or not to hand-feed colostrum to a newborn beef calf?
6 What volume of colostrum should be fed to a newborn beef calf?
253
chapter
44
Managing
Colostrum
1 What is colostrum?
• Colostrum (or “beestings”) is the first milk that the cow
produces after calving.
• Colostrum contains antibodies from the mother necessary to protect the calf from disease. Antibodies and other
protective mechanisms in colostrum help to maintain
the calf’s health and reduce mortality rates by helping to
eliminate bacteria and viruses.
3 What are the main factors affecting yield
and quality of colostrum?
Colostrum yield
Yield of colostrum is very variable between beef suckler cows
but is generally higher in:
• Beef × dairy cows than beef × beef or purebred beef breed cows.
• Colostrum is also a concentrated source of energy
• Beef breeds with greater milk yield potential.
and nutrients, with levels of protein, lactose, fat, and
vitamins A and E, much higher than found in milk.
• Older cows compared to heifers (first-calvers).
2 Why is consuming colostrum critical for
calf health and survival?
• Calves are born with a very poorly developed immune
system. Until their own immune system is fully functional,
at about 1 to 2 months of age, calves are dependant on
the passive immunity provided through absorption of
antibodies in colostrum from the cow.
• Calves that don’t receive enough colostrum are more
susceptible to neonatal infections and disease and,
in extreme cases, death.
• The antibodies present in the cow’s colostrum relate
to disease organisms in the local environment and also
to specific vaccines the cow received for control of
organism(s) known to be responsible for calf infection
on the farm e.g. E. coli, rotavirus and coronavirus.
• Cows that are adequately fed during late pregnancy
compared to those that are severely feed restricted
during this time – this especially applies to first-calvers
and very thin cows.
Colostrum quality (antibody concentration)
• Within most suckler beef cow breed types, colostrum
yield rather than colostrum antibody concentration is
the primary limiting factor.
• Antibody concentration (quality) in colostrum from suckler
beef cows is generally much higher (up to double) than in
dairy cows, but relatively similar for beef and beef
crossbred cows.
• Unlike dairy breeds, where colostrum antibody
concentration is usually much lower for first-calvers
compared to older cows, this doesn’t occur to the same degree with beef suckler cow breed types.
• Antibody concentration (quality) is similar between
quarters (teats) of the udder and is also similar within
a quarter, that is, as the quarter is milked / suckled out
for the first time.
• The antibody concentration of second milking colostrum
is only half that of first milking colostrum. This highlights
the importance of first-milking colostrum.
• Pre-partum leakage of colostrum from the udder results
in low antibody concentrations.
Colostrum antibody mass (i.e. colostrum volume x
antibody concentration) is more important than either
colostrum yield or antibody concentration alone.
254
chapter
44
23
4 What are the main factors affecting calf im- 5 When should you decide whether or not
mune status?
to artificially feed colostrum to a newborn
beef calf?
Passive immunity in suckler calves depends primarily on
Checklist
the colostrum antibody mass consumed, coupled with the
absorption capacity of the calf. Factors affecting these
Factors to consider before making
parameters impacts on the immune status of beef calves.
a decision:
• The antibodies in colostrum must get into the calf’s
• Is the calf too weak to suckle soon after birth?
blood via absorption from the small intestine.
• Has the cow abandoned the calf or refused the calf
• It is vital that sufficient colostrum is consumed as soon
as possible after birth because the ability of the calf to
absorb antibodies starts to decline after birth.
This happens progressively after 4 to 6 hours, and
ceases around 24 hours after birth.
The earlier a calf suckles (or is fed),
the greater the level of immunoglobulin
absorption.
Key Facts
Immune status is generally higher in
calves from:
“
“
“
Key Point
“
• The suckler herd than the dairy herd.
• Beef x dairy cows than from beef crossbred cows.
• Cow beef breed types with higher milk production
potential than from cows with lower milk production
potential.
• Older cows than heifers (first-calvers).
access to suckle soon after birth?
• Has the calf experienced a difficult birth or was it exposed to environmental conditions that might interfere with its ability to suckle?
• Has the cow sufficient colostrum for the calf?
If you answered yes to any of these questions, you may need
to hand-feed colostrum to the calf. Colostrum may be fed to
calves using a nipple bottle or a stomach tube (oesophageal
feeder). A stomach tube is particularly useful where the calf
is unable or unwilling to suckle. However, training/experience
is required in using this device.
6 What volume of colostrum should be fed to
a newborn beef calf?
• Calves should suckle the cow until they are full as soon
as possible after birth.
In situations where this is not feasible, research at Teagasc,
Grange has shown that feeding the calf 5% of its birth weight
(e.g. ~2 litres of colostrum for a 40 kg calf), within one hour
or so of birth, with subsequent suckling of the dam
(or a second feed) 6 to 8 hours later, ensures adequate
passive immunity.
• Cows adequately fed before calving compared to those
severely feed restricted (e.g. straw-only diet) before
calving.
255
256
chapter
Section 7
45
23
Dehorning/Disbudding,
Castration
by Bernadette Earley
Introduction
Beef cattle are disbudded/dehorned in order to reduce animal injuries
and damage to hides, improve human safety, reduce damage to facilities
and facilitate transport and handling.
Castration decreases the management problems associated with
aggressive and sexual behaviour of bulls.
1
2
3
4
What is the best age to disbud calves?
What are the legislative requirements aimed at ensuring humane disbudding
of calves?
What are the main methods used for disbudding of calves versus dehorning
older animals?
What are the legal requirements when castrating animals?
5 What are the main methods used for castrating bulls?
6 Is there any advantage in delaying castration of cattle?
257
chapter
45
Dehorning/Disbudding,
Castration
Where it is necessary to dehorn beef cattle, seek guidance from a veterinary
practitioner as to the optimum method and timing for the type of cattle and production system.
1 What is the best age to disbud calves?
Where practical, calves should be disbudded while horn
development is still at the horn bud stage as the horn buds
are not yet attached to the skull. Consequently, the procedure
involves less tissue trauma and is less stressful. Disbudding
is significantly less stressful than dehorning of older cattle.
• Use a cauterisation method (i.e. a heated disbudding iron) at one-two weeks to remove the horn buds.
• A custom-built calf dehorning crate will minimise stress
to the calf and ensure optimum safety to the operator.
2 What are the legislative requirements
aimed at ensuring humane disbudding
of calves?
Disbudding of calves is carried out to comply with
Regulations under the Diseases of Animals Act, (1966) which
prohibits the sale or export of horned animals. Disbudding
procedures must be carried out in compliance with the
Animal Health & Welfare Bill (2014).
Currently the legislation concerning dehorning of cattle
requires that once calves are over two weeks of age
disbudding may only be performed using with local
anaesthesia. It is illegal to disbud a calf over two weeks
old without using a local anaesthetic.
• Veterinary advice is that all calves should be treated
with a local anaesthetic when disbudding.
• Local anaesthetic may be obtained on prescription
from veterinary surgeons.
• Disbudding calves correctly is unlikely to produce
regrowth/’stumps’ preventing welfare problems and
possible rejection at marts later in life.
• Cattle cannot be marketed with horns. Marts will be guided
258
by the document “Dealing with horns on cattle best
practice” when accepting or rejecting animals for sale.
http://www.agriculture.gov.ie/media/migration/animal
healthwelfare/animalwelfare/horned_cattle_best_practice.pdf
3 What are the main methods used for disbudding of calves versus dehorning
older animals?
Methods of disbudding at the horn bud stage include removal
of the horn buds with a knife, or thermal cauterisation of the
horn buds.
Ensure that:
• A cauterisation method (i.e. using a heated disbudding iron) is used at one to two weeks to remove the horn buds.
• A custom-built calf dehorning crate is used to minimise stress to the calf and for optimum safety to the operator.
• Chemical paste to cauterise the horn buds is not
recommended.
• Once horn development has commenced horn cutting
or sawing at the base of the horn close to the skull
is needed.
• Producers should seek guidance from veterinarians
on the availability and advisability of analgesia/anaesthesia for dehorning of cattle, particularly in older animals,
where horns are more advanced.
• Operators performing either disbudding of calves or
dehorning of older cattle should be trained and competent
in the procedures used, and be able to recognise the signs
of complications.
chapter
45
23
Castration
4 What are the legal requirements when castrating animals?
In Ireland, use of anaesthesia is required for surgical/
Burdizzo castration of cattle over six months of age
(Animal Health & Welfare Bill (2014)). Rubber ring castration
(or use of other devices for constricting the flow of blood
to the scrotum) without use of anaesthesia can only
be performed in calves less than seven days of age (Oireachtas (Ireland), 1965)]. Where anaesthesia is required for castration, the procedure must be performed by a veterinary practitioner.
5 What are the main methods used for castrating bulls?
Burdizzo castration is based on the principle that crushing
destroys the spermatic cord carrying blood to the testicles but
that the skin of the scrotum remains intact. Each spermatic
cord is crushed twice (second crush below the first) for
10 seconds each along the neck of the scrotum with the
Burdizzo to ensure completeness of the castration procedure.
The Burdizzo must be in good condition. The jaws must be
parallel and close uniformly across their width so pressure
will be even across the jaws. Leave the Burdizzo slightly open
when not in use.
With the Burdizzo technique, the testicle is left to atrophy in
the scrotum, and because of the lack of open wounds the
potential for haemorrhage or infection is minimised. Infection
or maggot infestation is rare.
Techniques used to castrate male cattle include the
application of rubber rings or tightened latex bands, surgical
removal of the testicles, and use of a Burdizzo instrument to
crush the testicular cords.
Surgical castration
Knife cut
There are two principal surgical techniques for castrating
male cattle that are performed by a veterinary practitioner.
The first technique involves excision of the distal one-third
of the scrotum with a scalpel or sharp castration knife, to
expose the testicles by descent through the scrotal incision.
In the second technique, the lateral scrotal walls are incised
with a scalpel or a Newberry knife to expose the testicles in a
vertical fashion. The advantage of the Newberry knife is that
both the lateral walls and the median septum are simultaneously incised, thereby enhancing wound drainage. Proper
surgical hygiene must be observed during the castration
procedure to avoid any unnecessary cross-contamination,
infections or sepsis. Concurrent clostridial immunisation is
recommended.
Newberry knife
Emasculator
Burdizzo and Bander Instruments
Banding castration involves the application of a specially
designed elastic band with the aid of an applicator around
the neck of the scrotum, proximal to the testicles. This will
cause ischaemic necrosis of the testicles, eventually leading
to testicular atrophy and sloughing of the scrotum.
Small rubber rings are used for calves less than one month of
age (rubber ring castration), and for older calves, a heavy wall
latex band is used along with a grommet to securely fasten
the tubing at the appropriate tension. Tetanus has been
reported in banded calves; therefore animals should receive
tetanus prophylaxis to minimise the risk.
Proper immunization controls tetanus risk and Tetanus toxoid
(not anti-toxin) must be used. It is important to read and
follow vaccine instructions carefully and to vaccinate animals
at least one-month before carrying out the procedure and
again administer a booster vaccine on the day of banding.
259
chapter
6 Is there any advantage in delaying
castration of cattle?
There is a general perception among producers that delaying
castration could extend the production advantages of keeping
animals as bulls beyond puberty or weaning. After puberty,
bulls always grow faster than castrates, but the live-weight
advantage is largely lost when the bulls are ultimately
castrated.
A number of studies have shown no advantage in
delaying castration up to 17 months of age in terms of
slaughter weight or carcass weight at 22 months.
260
Key Point
“
Do not try to castrate animals until you have been
taught and are guided by someone experienced in
the proper techniques.
“
45
Dehorning/Disbudding,
Castration
chapter
Section 7
46
23
Managing
Weaning
by Bernadette Earley and Mark McGee
Introduction
Weaning breaks the maternal-offspring bond and removes milk from the calf’s diet.
This is stressful for the calf and happens at a time when other stress factors, e.g. change of environment (outdoors to indoor winter housing), change of forage diet (grazed
grass and to conserved forage usually with concentrate supplementation),
and transport/marketing may be encountered.
1 Why is it so important to reduce weaning stress?
2 What are the guiding principles for weaning management?
3 What are the main animal health risks at and post-weaning?
4 What are the key housing requirements for weaned calves?
261
chapter
46
Managing
Weaning
1 Why is it so important to reduce weaning
stress?
Stress has a negative effect on the immune system, making
calves more susceptible to disease. For the recently-weaned
calf, susceptibility to pneumonia or bovine respiratory disease
can be a particular problem.
2 What are the guiding principles for weaning management?
Weaning procedure
Avoid abrupt weaning of all animals at the one time.
Gradual weaning is better. Calves should be weaned in
at least two separate groups with each cow group being
removed at a minimum interval of five days.
Feeding concentrates pre-weaning.
Research at Teagasc Grange has shown that single-suckled
beef calves supplemented with concentrates prior to weaning
were less immune-compromised, started consuming meal
faster when housed indoors, and spent more time lying down
(rather than standing and walking) post-weaning compared
with non-supplemented calves.
Weanling pneumonia
• Clinical signs: Early diagnosis is essential for treatment
success and frequent observation is recommended post
weaning and after housing. Initial signs of pneumonia can
be non-specific for respiratory disease such as being ‘off
form’, dullness, reduced feed intake and lack of gut fill. Other signs may include fever (over 39.5 degrees C),
increased respiratory rate, watery discharge from the nose
and eyes. Later signs include purulent nasal discharge,
and severe respiratory distress. By the time these are
noted the disease is advanced. If you suspect weanling
pneumonia consult your local veterinary practitioner for
advice on diagnosis and treatment.
At pasture: Introduce concentrates one month prior to
weaning and gradually increase the allowance with the
intention of having the calf consuming one kg/day at
weaning time. Continue to feed the concentrates for at
least two weeks after weaning.
• Causes: Pneumonia is usually caused by a range of
pathogens, both viral ((Bovine Respiratory Syncytial Virus
(BRSV), Bovine ParaInfluenza 3 (BPI3), and Infectious
Bovine Rhinotracheitis (IBR)) also known as (Bovine herpes
virus 1 (BoHV-1)) and bacterial (Pasteurella multocida,
Mannheimia haemolytica, Histophilus somni, Mycoplasma
bovis). However, pneumonia is a classical multi-factorial
disease, and it is the combination of these infectious
agents with inappropriate management and husbandry
factors that causes outbreaks of the disease. In addition
the BVD virus can supress the immune system and lead to
pneumonia.
Indoors: Allow the calves access to cows in an adjacent
pen and offer the calves forage ad lib while simultaneously
increasing the concentrate allowance gradually over a
two-week period to one kg/day. After this period, calves’
access to cows can be ended.
• Unfavourable environmental conditions and stress usually
lead to viral infection of the lungs which is then followed by
bacterial infection. Bacterial infection causes the main
damage to the lungs which can be irreversible and lead to
ill-thrift or death if treated too late or not long enough.
Avoid additonal stressors at weaning.
e.g. calves should be castrated at least four weeks prior to
weaning date, or at least two weeks after the calf has been
weaned.
Treatment
There may also be advantages in delaying housing of recently
weaned calves.
262
3 What are the main animal health risks at
and post-weaning?
• Preventing pneumonia by managing weaned calves as
detailed above is preferable to treating outbreaks.
Antibiotics are ineffective against viral infections.
However, where bacterial involvement is suspected
antibiotic treatment is required. Anti-Inflammatory
drugs may also be useful.
chapter
46
23
• The most important factor for treatment success is to start
treatment very early in the course of the disease. The next
most important factor is to ensure treatment is long
enough – your veterinary practitioner will advise on the
course of therapy required. They can also advise on the
need to treat all animals within the group.
• Vaccinations: calves should be vaccinated where specific
problems arise and according to label recommendations.
Veterinary advice should be sought for a suitable
vaccination programme and the widest protection will be
achieved where the programme includes the three most
common respiratory viruses ((BRSV), (BPI3), (IBR or BoHV 1)). Vaccinations help reduce the probability of disease but
cannot solely be depended upon for prevention. The
management system pre- and post-weaning will assist the
successful outcomes of a bovine respiratory disease
vaccination programme.
Other considerations
• A review of current housing and environment is
recommended if there is a risk of weanling pneumonia.
• Isolation of individual sick animals is recommended.
• Plan a programme for purchasing weanlings where
stress is minimised and where purchased groups are
acclimatised outdoors or in open buildings before winter
housing.
Stomach worms and hoose
Calves should be treated for stomach worms and hoose
during the grazing season and for Ostertagia Type II worms
at housing using effective anthelmintics administered
according to product recommendations.
4 What are the key housing requirements for
weaned calves?
• All houses should be adequately ventilated allowing for
an adequate supply of fresh air thus prohibiting conditions
for viral growth and spread, allowing heat dissipation and
preventing the build-up of carbon dioxide, ammonia or
slurry gases.
• Surfaces should be even and non-slip to avoid
unnecessary underfoot conditions.
• There should be sufficient space for all animals to feed
comfortably at the same time. The feed trough should be
sufficiently large so that animals have adequate access to
feed at all times.
• Housed stock should have freedom of movement and
ample floor space for lying, grooming and normal animal
to animal interactions. High stocking densities may have an
adverse effect on growth rate, feed efficiency, carcass
weight and behaviour (e.g. locomotion, resting, feeding and
drinking).
Calves with pre-damaged lungs from lungworm infestation
also have a higher risk of developing pneumonia.
Grass tetany
Cows can be in danger of getting hypomagnesaemia
(grass tetany) immediately after weaning as a result of stress.
Feed calcined magnesite (60g/cow/day) for 4 to 5 days after
weaning.
263
264
chapter
Section 7
47
23
Animal
Welfare
by Bernadette Earley
Introduction
Animal welfare is concerned with the wellbeing of the animal and can be studied
through observations of animal behaviour and physiology. Animal welfare complements
the objectives of beef assurance schemes that demonstrate the production of safe beef to
consumers and food-chain stakeholders through welfare-friendly management
practices. Good farm animal welfare is an integral part of Irish beef farming which is
largely grass-based and extensive. Irish agriculture and Irish farmers operate to a very
high standard of animal welfare. Animal welfare is strongly regulated in Ireland through
the Department of Agriculture, Food & the Marine (DAFM) cross-compliance inspection
system, which all Irish farmers have to comply with.
1 How will I achieve best animal welfare practices in my herd?
2 What are the most important environmental requirements of farm animals to attain optimal welfare?
3 What measures can be used on farms to assess animal welfare?
4 What is the role of the stockperson in ensuring optimum animal welfare?
265
chapter
Animal
Welfare
47
1
How will I achieve best animal welfare
practices in my herd?
The concept of the ‘Five Freedoms and Provisions’
(Farm Animal Welfare Council www.fawac.ie) is a
guide to achieving best animal welfare practices:
Freedom from hunger and thirst - providing fresh water
and the right amount of feed to keep animals healthy.
Freedom from discomfort - making sure that your animals
have the right kind of environment, including shelter and
somewhere comfortable to rest.
Freedom from pain, injury and disease - preventing your
animals from getting ill and making sure that animals are
diagnosed and treated rapidly should they fall ill.
Freedom to express normal behaviour - making sure that
your animals have adequate space and proper facilities.
Freedom from fear and distress - making sure that
animals’ conditions and treatment avoid mental suffering.
2 What are the most important environmental requirements of farm animals to attain optimal welfare?
The main environmental requirements of farm animals
are comfort, security, hygiene and freedom to perform
behaviours.
Comfort Security
Hygiene
Behaviour
266
Thermal - neither too hot nor too cold.
Physical - a suitable resting area.
Space for grooming, limb-stretching
and exercise.
of food and water supply, from death
or injury due to predation, aggression,
floods etc. from fear of predation or
aggression.
to reduce the risk of disease,
to avoid the discomfort of squalor.
to permit coping behaviours,
to allow animals to acquire security
through experience and adaptation
to the normal sights and sounds of
farm activity.
3 What measures can be used on farms to
assess animal welfare?
In general, two broad categories of parameters can be used
for practical welfare assessment on-farm.
“Environmental” parameters:
These are specific standards for housing and management
systems.
Housing standards include, for example, adequate space
allowance, feeder space, number and flow rates of
drinkers, floor types, etc. Husbandry and management
standards may include such factors as specific ages
and/or techniques for castration and processing, and
appropriate training for stockpersons.
“Animal-Based Parameters”. These include measures
of the animals’ reactions or responses to the production
system. Cow replacement rate, herd fertility indices and
calf survival indices (in breeding herds); Bodyweight-for-age
(average daily gain) for the breed, cross or gender;
Body condition scores (BCS); Records of deaths; Veterinary
treatments; Incidence of disease and injury.
4 What is the role of the stockperson in ensuring optimal animal welfare?
The stockperson is key to ensuring optimal animal welfare.
Specific stockpersonhip skills may be developed on-farm,
working with an experienced person, or by following a course
offered by a suitable training organisation. Wherever possible,
the training should lead to formal recognition of competence.
Without competent, diligent, stockpersonship animal welfare
will be compromised.
chapter
47
Checklist
A competent stockperson should be
able to:
• Recognise whether or not the animals are in good health. Signs of ill health include: loss of appetite, listlessness,
cessation of cudding, discharge from eyes or nostrils,
dribbling, persistent coughing, lameness, swollen joints,
scouring, rapid loss of condition or emaciation, excessive
scratching, abnormal skin conditions or other unusual conditions.
• Understand the significance of a change in the behaviour of the animals.
• Know when veterinary treatment is required.
• Implement a planned herd health programme (e.g.
preventative treatments, vaccination programmes if
necessary).
• Implement appropriate animal feeding and grassland management programmes.
• Recognise if the general environment (indoors or outdoors) is adequate for the promotion of good health and welfare.
• Have management skills appropriate to the scale and technical requirements of the production system.
• Handle animals with care, avoiding undue stress.
Footnote
Farm Animal Welfare Advisory Council (FAWAC)
The Farm Animal Welfare Advisory Council (FAWAC) was
established in 2002 as an advisory body to the Minister
(DAFM), bringing together, for the first time in Ireland,
representatives of the principal stakeholders from animal
welfare organisations, farming bodies, Government
Departments (North and South), the veterinary
representative body and representatives from education and
research. The FAWAC provides a valuable forum, bringing
together a diverse range of interests and enabling
representatives to meet, exchange divergent views and reach
consensus on the broad mandate of challenges facing farm
animal welfare. All members have a common purpose and
share the view that animal welfare is an issue of very high
importance. It has been particularly successful in publishing
a series of welfare guideline booklets across a wide range
of animals and activities which can be found on the website
www.fawac.ie
Herding
• Daily routines should be carried out calmly and
consistently with the aim of accustoming the animals
to the normal sights and sounds of farm activity.
Farm animals have a natural fear of novelty. Once the
sights and sounds become routine, animals acquire a
sense of security.
• A good stockperson will individually inspect all animals
at least once per day. Particular categories of animals will
require more frequent inspection, e.g. young calves or
cows in late pregnancy.
• Formal training and/or experience working under the
supervision of a competent stockperson is strongly
recommended where inexperienced persons are taking
over responsibility for animal husbandry on a farm.
• Common veterinary activities (e.g. dosing, injecting,
and castration) should not be attempted without direct
appropriate supervision until the stockperson is competent to carry out these activities.
• Stockpersons already involved in animal management/
husbandry should keep themselves updated in
technological developments that can prevent or correct welfare problems.
Handling of animals
• Animals must be handled with care and patience.
When restraint is needed it should be minimised in
degree and duration. Particular care is needed in handling the calving cow and the newborn calf. Care in handling
of bulls is of utmost importance, particularly from the
operators’ safety viewpoint.
267
268